Recently, a cluster system capable of simultaneously process a plurality of substrates is commonly employed in substrate processing systems for manufacturing liquid crystal displays, plasma panel displays, and semiconductor devices.
In general, the cluster system refers to a multi-chamber type substrate processing system including a transfer robot (or a handler) and a plurality of substrate processing modules provided around the transfer robot.
The cluster system includes a transfer chamber and the transfer robot provided in the transfer chamber to be freely rotatable. Process chambers for performing processes of processing substrates are mounted to the sides of the transfer chamber. Such a cluster system simultaneously processes a plurality of substrates or continuously performs various processes to increase an amount of processing substrates. In order to increase the amount of processing substrates, a plurality of substrates is simultaneously processed in a single process chamber to increase the amount of processing substrates per unit time.
However, although the plurality of substrates is simultaneously (or continuously) processed in the process chamber, when substrates before and after being processed are not effectively exchanged in the process chamber, loss of time is generated.
Moreover, when a conventional cluster system includes a hexagonal transfer chamber (basically, including four process chambers and two load lock chambers), due to the area occupied by the transfer chamber, the area of the cluster system and the width of the entire cluster system that is important to the arrangement of the cluster system in a manufacturing line increases more than a desired width and the scale of a vacuum system required for maintaining the transfer chamber in a vacuum state increases, so that apparatus cost and installation cost increase. In addition, the area of the transfer chamber more increases as the number of provided process chambers increases.
Thus, a substrate processing system capable of simultaneously (or continuously) processing the plurality of substrates and of effectively exchanging the substrates before and after being processed in the process chamber to process the plurality of substrates is required.